Uncoupling protein 2 combats oxidative damage to human sperm / 中华男科学杂志

<p><b>OBJECTIVE</b>Germ cells are much more susceptible to oxidative stress than somatic cells. Accumulating evidence indicates that uncoupling protein 2 (UCP2) prevents the apoptosis of multiple types of cells induced by reactive oxygen species (ROS). The present study aimed to evaluate the protective effect of uncoupling protein 2 (UCP2) against oxidative damage to human sperm.</p><p><b>METHODS</b>Semen parameters were obtained from 97 semen samples by computer assisted sperm analysis (CASA), and the samples, based on the percentage of grade a + b sperm, allotted to Groups I (n = 25, grade a + b sperm > 50%), II (n = 24, grade a + b sperm 25%-50%), III (n = 24, grade a + b sperm 10-25%) and IV (n = 24, grade a + b sperm < 10%). The expressions of sperm UCP2 mRNA was detected by RT-PCR, and the malonaldehyde (MDA) content in ROS was determined in the sperm suspension.</p><p><b>RESULTS</b>The expressions of UCP2 mRNA in sperm were 1.51 +/- 0.24, 1.28 +/- 0.15, 1.17 +/- 0.20 and 0.69 +/- 0.18, and the MDA contents were (14.66 +/- 2.55), (16.00 +/- 2.09), (17.44 +/- 1.40) and (21.20 +/- 3.50) nmol/10(8) sperm in Groups I, II, III and lV, respectively. There was a significant negative correlation between the expression of UCP2 mRNA and the content of MDA (r = -0.633, P < 0.01), the former obviously reduced while the latter remarkably increased in the groups of lower sperm motility (P < 0.01).</p><p><b>CONCLUSION</b>UCP2 plays an important protective role against oxidative stress damage to human sperm by diminishing ROS production.</p>

Expression of uncoupling protein 2 on macrophages and its relation to interleukin-10/interferon ratio in patients with unexplained recurrent spontaneous abortion / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the relationship between the expression of uncoupling protein 2 (UCP2) and ratio of interleukin-10/interferon-gamma (IL10/IFNgamma) in the macrophages from patients with unexplained recurrent spontaneous abortion (URSA).</p><p><b>METHODS</b>Twelve women undergoing selective termination of normal early pregnancy (control) and 11 having URSA were included in this study. Magnetic cell sorting (MACS) was used to isolate the macrophages in the decidua, and the expression of UCP2 was detected with flow cytometry. Cytokine (IL10 and IFNgamma) secretion by the macrophages was detected by enzyme-linked immunosorbent spot-forming (ELISPOT) cell assay.</p><p><b>RESULTS</b>Compared to the control group, the women with URSA showed significantly decreased expression of UCP2 on decidual macrophage (136-/+25 vs 201-/+31, P<0.01), and the expression of UCP2 was positively correlated to the ratio of IL10/IFNgamma(r=0.73, P<0.01).</p><p><b>CONCLUSION</b>UCP2 may play an important role in the regulation of macrophage activity and cytokine secretion to contribute to spontaneous abortion.</p>

Uncoupling protein-2 expression in granular cells and embryo development in in vitro fertilization-embryo transfer cycle / 南方医科大学学报

<p><b>OBJECTIVE</b>To examine the expression of uncoupling protein-2 (UCP2) in the granular cell of women undergoing in vitro fertilization (IVF) and explore its role in embryo development.</p><p><b>METHODS</b>In this prospective study, the levels of UCP2 and reactive oxygen species (ROS) were measured by the chemiluminescence method in the granular cell of 53 women.</p><p><b>RESULTS</b>Women with low UCP2 level had higher ROS level, suggesting an inverse relationship between them (r=-0.578, P<0.01), and their oocyte development was impaired. Granular cells of elder women exhibited lowered UCP2 expression.</p><p><b>CONCLUSION</b>The granular cells increase UCP2 expression to suppress the elevation of intracellular ROS level through a feedback mechanism and therefore protect the oocytes against oxidative stress.</p>